This invention relates to a method of recording a handwritten message such as a signature in digitized form. It has particular application to commercial transactions wherein a handwritten signature is captured at a point of sale and is stored for later use to authenticate the transaction, authorize an automatic account debit or the like. The invention is particularly well suited for use with merchandising systems of the type disclosed in Allgeier et al, application Ser. No. 575,096, filed Aug. 30, 1990 and in Kapp et al, application Ser. No. 640,199, filed Jan. 11, 1991, the disclosures of which are incorporated herein by reference.
Merchandising systems as described in the above-mentioned patent applications are equipped with a transparent glass screen having a resistive coating fused to its surface. A linearized voltage field is established on the surface of the screen. A human signature is captured by providing a hand-held stylus which is moved across the surface of the screen during writing of the signature. A digitizer senses the position of the stylus during writing of the signature and generates digital signals representing the X-Y coordinates of the stylus. The digitized coordinates are stored in a memory and are also used to drive a liquid crystal display positioned below the glass screen. This produces a visual display of the signature, as the handwriting progresses. Means are provided for maintaining the signature in registration with the movement of the stylus, as disclosed in detail in the above-mentioned patent applications. Preferably, a skew correction is employed in the signature registration as disclosed in Crooks et al, Ser. No. 640,321, filed Jan. 11, 1991, also incorporated herein by reference.
The system of the above applications preferably includes a work station such as an NCR 7052 Work Station equipped with a built-in microprocessor and a keyboard for entering transaction data. A printer may be provided for printing transaction data and a replica of the signature on a suitable paper receipt.